Postmortem bacteriology and pneumonia in a mentally retarded population.

Postmortem pathologic and bacteriologic reports were analyzed for 237 deaths occurring at a large institution for the mentally retarded from 1958 to 1973. Bronchopneumonia, aspiration pneumonia, and lipid pneumonia were frequently reported at autopsy, and in a total of 146 cases (61.6%) at least one type of pneumonia was reported. Postmortem bacteriologic cultures in a smaller group revealed high recovery rates of staphylococci (coagulase-positive), hemolytic streptococci, and gram-negative bacilli in throat and lung cultures. Enteric aerobic gram-negative bacilli were particularly frequent along with yeast (Candida albicans). The institutionalized retarded appear similar to other hospitalized populations, in that a large proportion of hospital-acquired respiratory infections is related to aerobic gram-negative bacilli. The high frequency of aspiration and its sequelae in this population is unusual, however, and post-mortem bacteriologic findings appear consistent with those of antemortem studies of cases of aspiration pneumonia.